6-heterocyclic-4-amino-1,2,2A,3,4,5-hexahydrobenz[cd]indoles

ABSTRACT

6-Heterocyclic-4-amino-1,2,2a,3,4,5-hexahydrobenz-[cd]indoles are provided which are useful in modifying the function of serotonin in mammals.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of application Ser. No.08/263,910, filed Jun. 20, 1994, which is a divisional application ofapplication Ser. No. 07/954,171, filed Sep. 30, 1992, now issued as U.S.Pat. No. 5,347,013, which is a continuation-in-part application ofapplication Ser. No. 07/676,679, filed Mar. 28, 1991, now issued as U.S.Pat. No. 5,244,911.

FIELD OF THE INVENTION

This invention relates to6-heterocyclic-4-amino-1,2,2a,3,4,5-hexahydrobenz[cd]indoles and theiruse in modifying the function of serotonin in a mammal.

BACKGROUND OF THE INVENTION

Flaugh in U.S. Pat. No. 4,576,959 (issued 1986) disclosed a family of6-substituted-4-dialkylamino-1,3,4,5-tetrahydrobenz[cd]indoles which aredescribed as central serotonin agonists. Leander in U.S. Pat. No.4,745,126 (1988) disclosed a method for treating anxiety in humansemploying a 4-substituted-1,3,4,5-tetrahydrobenz[cd]indole-6-carboxamidederivative.

European Patent Application 399,982 discloses certainheterocyclic-substituted aminotetralins. These compounds are disclosedas being serotonin agonists, partial agonists or antagonists.

It has now been found that certain 6-heterocyclic-substitutedhexahydrobenz[cd]indoles are useful in treating conditions requiringmodification of the serotonin function in the body.

SUMMARY OF THE INVENTION

This invention relates to compounds of the Formula 1 ##STR1## wherein:R¹ is hydrogen, C₁ -C₄ alkyl, C₃ -C₄ alkenyl, cyclopropylmethyl, aryl(C₁-C₄ alkyl), --(CH₂)_(n) S(C₁ -C₄ alkyl), --C(O)R⁴, --(CH₂)_(n) C(O)NR⁵R⁶ ;

R² is hydrogen, C₁ -C₄ alkyl, cyclopropylmethyl or C₃ -C₄ alkenyl;

R³ is hydrogen, C₁ -C₄ alkyl or an amino-blocking group;

n is 1-4;

R⁴ is hydrogen, C₁ -C₄ alkyl, C₁ -C₄ haloalkyl, C₁ -C₄ alkoxy or phenyl;

R⁵ and R⁶ are independently hydrogen, a C₁ -C₄ alkyl, or a C₅ -C₈cycloalkyl, with the proviso that when one of R⁵ or R⁶ is a cycloalkylthe other is hydrogen;

HET is a tetrazolyl ring, a substituted tetrazolyl ring or an aromatic5- or 6-membered heterocyclic ring, said ring having from one to threeheteroatoms which are the same or different and which are selected fromthe group consisting of sulfur, oxygen, and nitrogen with the provisothat the 6-membered heterocyclic ring can only contain carbon andnitrogen and with the further proviso that the 5-membered ring maycontain no more than one oxygen or one sulfur but not both oxygen andsulfur.

The invention also provides a pharmaceutical formulation comprising acompound of Formula 1 in combination with a pharmaceutically acceptableexcipient therefor.

A further embodiment of the invention is a method for effecting abiological response at the 5HT_(1A) or 5HT_(1D) receptor byadministering a compound of Formula 1. Another embodiment involves amethod for treating a variety of conditions in a mammal which requireregulation of serotonin functions by administering a compound of Formula1.

DETAILED DESCRIPTION OF THE INVENTION

As used herein, the term "alkyl" represents a straight or branched alkylchain having the indicated number of carbon atoms. For example, "C₁ -C₄alkyl" groups are methyl, ethyl, n-propyl, isopropyl, n-butyl,sec.-butyl, isobutyl and tert-butyl. "C₁ -C₈ alkyl" groups include thoselisted for C₁ -C₄ alkyl as well as n-pentyl, 2-methylbutyl,3-methylbutyl, n-hexyl, 4-methylpentyl, n-heptyl, 3-ethylpentyl,2-methylhexyl, 2,3-dimethylpentyl, n-octyl, 3-propylpentyl,6-methylheptyl, and the like.

The term "C₃ -C₄ alkenyl" refers to olefinically unsaturated alkylgroups such as --CH₂ CH═CH₂, --CH₂ CH₂ CH═CH₂, --CH(CH₃)CH═CH₂ and thelike.

The term "aryl" means an aromatic carbocyclic structure having six toten carbon atoms. Examples of such ring structures are phenyl, naphthyl,and the like.

The term "cycloalkyl" means an aliphatic carbocyclic structure havingthe indicated number of carbon atoms in the ring. For example, the term"C₃ -C₇ cycloalkyl" means cyclopropyl, cyclobutyl, cyclopentyl,cycloheryl, and cycloheptyl.

The term "aryl (C₁ -C₄ alkyl)" means an aryl structure joined to a C₁-C₄ alkyl group. Examples of such groups are benzyl, phenylethyl,α-methylbenzyl, 3-phenylpropyl, α-naphthylmethyl, β-naphthylmethyl,4-phenylbutyl, and the like. Similarly the term "aryl (C₁ -C₃ alkyl)"means an aromatic carbocyclic structure joined to a C₁ -C₃ alkyl.

The C₁ -C₈ alkyl, aryl, aryl (C₁ -C₄ alkyl) and aryl (C₁ -C₃ alkyl)groups can be substituted by one or two moieties. Typical aryl and/oralkyl substitutents are C₁ -C₃ alkoxy, halo, hydroxy, C₁ -C₃ thioalkyl,nitro, and the like. Moreover, the aryl, aryl (C₁ -C₄ alkyl) and aryl(C₁ -C₃ alkyl) groups can also be substituted by a C₁ -C₃ alkyl or atrifluoromethyl group.

In the foregoing, the term "C₁ -C₃ alkyl" means any of methyl, ethyl,n-propyl, and isopropyl; the term "C₁ -C₃ alkoxy" means any of methoxy,ethoxy, n-propoxy, and isopropoxy; the term "halo" means any of fluoro,chloro, bromo, and iodo; and the term "C₁ -C₃ thioalkyl" means any ofmethylthio, ethylthio, n-propylthio, and isopropylthio.

Examples of substituted C₁ -C₈ alkyl are methoxymethyl, trifluoromethyl,6-chlorohexyl, 2-bromopropyl, 2-ethoxy-4-iodobutyl, 3-hydroxypentyl,methylthiomethyl, and the like.

Examples of substituted aryl are p-bromophenyl, m-iodophenyl, p-tolyl,o-hydroxyphenyl, β-(4-hydroxy)-naphthyl, p-(methylthio)phenyl,m-trifluoromethylphenyl, 2-chloro-4-methoxyphenyl, α-(5-chloro)naphthyl,and the like.

Examples of substituted aryl (C₁ -C₄ alkyl) are p-chlorobenzyl,o-methoxybenzyl, m-(methylthio)-α-methylbenzyl,3-(4'-trifluoromethylphenyl)propyl, o-iodobenzyl, p-methylbenzyl, andthe like.

The term "amino-blocking group" is used herein as it is frequently usedin synthetic organic chemistry, to refer to a group which will preventan amino group from participating in a reaction carried out on someother functional group of the molecule, but which can be removed fromthe amine when it is desired to do so. Such groups are discussed by T.W. Greene in chapter 7 of Protective Groups in Organic Synthesis JohnWiley and Sons, N.Y., 1981, and by J. W. Barton in chapter 2 ofProtective Groups in Organic Chemistry J. F. W. McOmie, ed., PlenumPress, N.Y., 1973, which are incorporated herein by reference in theirentirety. Examples of such groups include benzyl and substituted benzylsuch as 3,4-dimethoxybenzyl, o-nitrobenzyl, and triphenylmethyl; thoseof the formula --COOR where R includes such groups as methyl, ethyl,propyl, isopropyl, 2,2,2-trichloroethyl, 1-methyl-1-phenylethyl,isobutyl, t-butyl, t-amyl, vinyl, allyl, phenyl, benzyl, p-nitrobenzyl,o-nitrobenzyl, and 2,4-dichlorobenzyl; acyl groups and substituted acylsuch as formyl, acetyl, chloroacetyl, dichloroacetyl, trichloroacetyl,trifluoroacetyl, benzoyl, and p-methoxybenzoyl; and other groups such asmethanesulfonyl, p-toluenesulfonyl, p-bromobenzene-sulfonyl,p-nitrophenylethyl, and p-toluenesulfonylaminocarbonyl. Preferredamino-blocking groups are benzyl (--CH₂ C₆ H₅), acyl [C(O)R] or SiR₃where R is C₁ -C₄ alkyl, halomethyl, or 2-halo-substituted-(C₂ -C₄alkoxy).

The term "aromatic 5- or 6-membered heterocyclic ring" refers to a ringcontaining from one to three heteroatoms which can be nitrogen, oxygenor sulfur. The 5-membered heterocyclic rings can contain carbon andnitrogen atoms and up to one oxygen or one sulfur but not one of each.In 5-membered rings not containing oxygen or sulfur, one nitrogen can besubstituted with either a hydrogen, C₁ -C₃ alkyl, phenyl or (C₁ -C₃alkyl)phenyl group. The 6-membered heterocyclic rings can contain carbonand nitrogen atoms only. The 5- or 6-membered rings can have one or twoof the carbon atoms in the ring substituted independently with C₁ -C₃alkyl, halogen, OH, C₁ -C₃ alkoxy, C₁ -C₃ alkylthio, NH₂, CN or phenyl.Adjacent carbons in the heterocyclic ring may be connected with a--CH═CH--CH═CH-- bridge to form a benzo-fused ring on the heterocycle.

These aromatic 5- or 6-membered heterocyclic rings can be eithersubstituted or unsubstituted and include furan, thiophene, thiazole,oxazole, isoxazole, isothiazole, oxadiazole, thiadiazole, pyridine,pyridazine, pyrimidine, pyrazine, pyrrole, pyrazole, imidazole, andtriazole. The heterocyclic ring can be attached to the benzene ring byany carbon in the heterocyclic ring, for example, 2- or 3-furan.

The term "substituted tetrazolyl ring" refers to a tetrazolyl ringsystem which has a C₁ -C₃ alkyl or phenyl substituent on the 2-positionnitrogen atom of such ring system.

As used herein the following terms refer to the structure indicated andinclude all of the structural isomers: ##STR2##

While all of the compounds of the invention are useful for the purposestaught herein, certain of the present compounds are preferred for suchuses. Preferably R¹ and R² are both C₁ -C₄ alkyl, particularly n-propyl,R³ is hydrogen, and HET is one of the following isoxazole, oxazole,pyrazole, pyridine, thiazole, furan, thiophene or oxadiazole. Otherpreferred aspects of the present invention are noted hereinafter.##STR3##

The compounds of the instant invention have at least two chiral centersand therefore at least four stereoisomers can exist for each. Chiralcenters exist at positions 2a and 4 of Formula 1. If a substitutentgroup contains a chiral center, then additional stereoisomers can exist.Racemic mixtures as well as the substantially pure stereoisomers ofFormula 1 are contemplated as within the scope of the present invention.By the term "substantially pure", it is meant that at least about 90mole percent, more preferably at least about 95 mole percent and mostpreferably at least 98 mole percent of the desired stereoisomer ispresent compared to other possible stereoisomers. Particularly preferredstereoisomers of Formula 1 are those in which the configuration of thechiral center at position 2a is S and at position 4 is R, i.e., 2aS, 4R,or the configuration of the chiral center at position 2a is R and atposition 4 is S, i.e., 2aR,4S.

The terms "R" and "S" are used herein as commonly used in organicchemistry to denote specific configuration of a chiral center. The term"R" refers to "right" and refers that configuration of a chiral centerwith a clockwise relationship of group priorities (highest to secondlowest) when viewed along the bond toward the lowest priority group. Theterm "S" or "left" refers to that configuration of a chiral center witha counterclockwise relationship of group priorities (highest to secondlowest) when viewed along the bond toward the lowest priority group. Thepriority of groups is based upon their atomic number (heaviest isotopefirst). A partial list of priorities and a discussion of stereochemistryis contained in the book: The Vocabulary of Organic Chemistry Orchin, etal., John Wiley and Sons Inc., publishers, page 126, which isincorporated herein by reference.

As set forth above, this invention includes the pharmaceuticallyacceptable salts of the compounds of Formula 1. Since the compounds ofthis invention are amines, they are basic in nature and accordinglyreact with any number of inorganic and organic acids to formpharmaceutically acceptable salts using acids such as hydrochloric acid,nitric acid, phosphoric acid, sulfuric acid, hydrobromic acid,hydroiodic acid, phosphorous acid and others, as well as salts derivedfrom nontoxic organic acids such as aliphatic mono and dicarboxylicacids, amino acids, phenyl-substituted alkanoic acids, hydroxyalkanoicand hydroxyalkandioic acids, aromatic acids, aliphatic and aromaticsulfonic acids. Such pharmaceutically acceptable salts thus includesulfate, pyrosulfate, bisulfate, sulfite, bisulfite, nitrate, phosphate,monohydrogenphosphate, dihydrogenphosphate, metaphosphate,pyrophosphate, chloride, bromide, iodide, acetate, propionate,caprylate, acrylate, formate, tartrate, isobutyrate, caprate,heptanoate, propiolate, oxalate, malonate, succinate, suberate,sebacate, fumarate, maleate, mandelate, butyne-1,4-dioate,hexyne-1,6-dioate, hippurate, benzoate, chlorobenzoate, methylbenzoate,phthalate, terephthalate, benzenesulfonate, toluenesulfonate,chlorobenzenesulfonate, xylenesulfonate, phenylacetate,phenylpropionate, phenylbutyrate, citrate, lactate, β-hydroxybutyrate,glycolate, malate, naphthalene-1-sulfonate, naphthalene-2-sulfonate andmesylate.

Particularly preferred compounds of Formula 1 include the compounds inwhich R³ is hydrogen, R¹ and R² are both either n-propyl or methyl andHET is 3-isoxazolyl, 5-isoxazolyl, 2-oxazolyl, 5-oxazolyl,3-isothiazolyl, 5-isothiazolyl, 2-imidazolyl or 4-imidazolyl. Thesecompounds include the racemic mixtures of possible stereoisomers as wellas the substantially pure stereoisomers with different configurations atpositions 2a and 4, i.e., 2aR, 4R or 2aR, 4S or 2aS, 4R or 2aS, 4S.

As depicted in Scheme I, the compounds of the present invention can beprepared by reacting a 4-amino-6-metallo-substitutedhexahydrobenz[cd]indole as represented by structure 2 with aheterocyclic compound represented by structure 4- In structure 2, Mrepresents a metallo moiety such as lithium, magnesium, zinc, tin,mercury, boronic acid (--BO₂ H₂) and the like while Z is anamino-blocking group. When the metallo moiety is multivalent, it isnormally associated with other moieties such as, for example, halo formagnesium (Grignard reagent) and alkyl groups for tin (trialkyltin). Theheterocycle represented by structure 4 contains a leaving group "L",such as a chloro, bromo, or trifluoromethylsulfonoxy group, which can bedisplaced by the metallo-indole. The heterocycle can be substituted asset forth hereinabove. ##STR4##

The reaction of the metallo-indoline 2 and heterocycle 4 is accomplishedin the presence of a palladium or nickel catalyst such as Pd[P(C₆ H₅)₃]₄, PdCl₂, Pd[P(C₆ H₅)₃ ]₂ Cl₂, Ni(acac)₂, NiCl₂ [P(C₆ H₅)₃ ]₂ and thelike, wherein "acac" represents acetylacetonate and "C₆ H₅ " representsa phenyl group. The organometallic reagent 2 is prepared by methodscommonly used in the art for such preparations, for example, the lithiumor magnesium reagents can be prepared by contacting the appropriate6-chloro-, 6-bromo- or 6-iodo-substituted hexahydrobenzindole with anorganolithiumreagent or magnesium metal in a solvent such as ether ortetrahydrofuran. Other organometallic derivatives can be used such aszinc, tin, mercury or boronic acid (--BO₂ H₂). The zinc, tin and mercuryreagents can be prepared by reaction of the lithiated benzindole with azinc, tin or mercury derivative such as zinc chloride,chlorotrialkylstannane, or mercuric chloride. The boronic acidderivative can be prepared by reacting the lithium reagent withtrimethylborate followed by hydrolysis of the resulting boronate ester.Mercuric acetate can be contacted directly with the hexahydrobenzindoleto provide the mercurated derivative.

The 1-nitrogen of the hexahydro benzindole is preferably protected witha group such as triphenylmethyl (trityl), benzyl, or benzoyl. Theseprotecting groups are represented by Z in structures 2. The protectinggroup can be removed after the coupling reaction is accomplished toprovide the 1-hydrobenzindole compound.

An alternative method of preparing the compounds of the instantinvention involves contacting an organometallic reagent prepared from aheterocyclic compound with a 6-bromo or 6-iodo-4-aminobenzindole. Thereaction is accomplished in the presence of a catalyst such as that usedin reaction Scheme I. The metal in the organometallic derivative of theheterocycle can be lithium, magnesium (Grignard reagent), zinc, tin,mercury, or a boronic acid (--BO₂ H₂). These organometallic compoundscan be prepared by standard methods, as described above for thebenzindoles. Alternatively, the lithiated heterocycles can be preparedby treating a heterocycle with a strong base such as an alkyllithium ora lithium dialkylamide.

Unless otherwise indicated, in the following preparation procedures,R_(a) and R_(a) ' may independently be hydrogen, C₁ -C₃ alkyl, halogen,OH, O(C₁ -C₃ alkyl), S(C₁ -C₃ alkyl), NH₂, CN, or phenyl. R_(b) may behydrogen, C₁ -C₃ alkyl, phenyl, or (C₁ -C₃ alkyl)phenyl. R_(c) may behydrogen or C₁ -C₃ alkyl. R_(d) may be OH, O(C₁ -C₃ alkyl), O(phenyl),O(C₁ -C₃ alkylphenyl), halo, S(C₁ -C₃ alkyl), S(phenyl), S(C₁ -C₃alkylphenyl), NH₂, NH(C₁ -C₃ alkyl), N(C₁ -C₃ alkyl)₂, OCO(C₁ -C₃alkyl), OCO(phenyl), OCO(C₁ -C₃ alkylphenyl) or the like.

In an alternative preparation procedure, compounds of the instantinvention having a 5-membered heterocyclic ring in the 6-position can beprepared by the cycloaddition of a compound of the type represented instructure 8 wherein R¹ and R² are as defined above and B is anamino-protecting group or hydrogen, ##STR5## with a 1,3-dipole of thetype ⁺ T═U--V⁻ in which T, U, and V can be selected from the followinglist of (a) through (i).

    ______________________________________                                                  T        U          V                                               ______________________________________                                        (a)         CR.sub.a   N          CHR.sub.a                                   (b)         CR.sub.a   N          NR.sub.b                                    (c)         CR.sub.a   N          O                                           (d)         N          N          O                                           (e)         CR.sub.a   CR.sub.a ' NR.sub.b                                    (f)         CR.sub.a   CR.sub.a ' O                                           (g)         N          CR.sub.a ' CHR.sub.a                                   (h)         N          CR.sub.a ' NR.sub.b                                    (i)         N          CR.sub.a ' O                                           ______________________________________                                    

In this list R_(a) and R_(a) ' are not OH or NH₂, N represents nitrogenand O represents oxygen. This cycloaddition provides products of thestructure 10, wherein R¹ and R² are as defined above and B is an aminoprotecting group or hydrogen. ##STR6## The 1-nitrogen of structures 8and 10 can be protected using standard protecting groups preferably (C₂H₅)₂ NC(O)--, triisopropylsilyl, benzoyl, or benzenesulfonyl.

Alternatively, the 6-alkyne-substituted indole of structure 8 can bereacted with a dipole of the type ⁺ T--U═V⁻ in which T, U, and V areselected from the following list for (j) and (k):

    ______________________________________                                                   T        U     V                                                   ______________________________________                                        (j)          CHR.sub.a  N     N                                               (k)          NR.sub.b   N     N                                               ______________________________________                                    

In this list R_(a) is not OH or NH₂ and N is nitrogen. This reactionprovides products of structure 12, ##STR7## wherein R¹, R², R_(a) and Bare as defined above.

Alternative procedures for preparing certain of the instant compoundsare set forth hereinbelow in Schemes 2 through 19. As used in thesereaction Schemes, "Ar" refers to the1,2,2a,3,4,5-hexahydrobenz[cd]indole, with the indicated substituent inthe 6-position. In these Schemes, "Me" is methyl, "Et" is ethyl, "NBS"represents n-bromosuccinimide, R_(a), R_(b), R_(c) and R_(d) are definedabove, "MsCl" represents methanesulfonyl chloride, "Δ" represents heat,".o slashed." and "Ph" each represent phenyl, "DMF" representsdimethylformamide, "DMS" represents dimethyl sulfide, "TMS" representstrimethylsilyl, "[O]" represents an oxidant, Lawesson's reagent isp-methoxyphenyl-thionophosphine sulfide dimer, "Ac" represents acetyl,"NCS" represents N-chlorosuccinimide, "DCC" representsdicyclohexylcarbodiimide, "Im" represents 1-imidazolyl, and "[H]"represents a reductant. As set forth hereinabove, the 1-nitrogen of thebenz[cd]indole is normally protected with an amino blocking group,preferably triisopropylsilyl. ##STR8## where R is hydrogen, C₁ -C₃ alkylor phenyl

Scheme 20 illustrates a preparation of a starting material for reactionScheme 1. ##STR9##

In Scheme 20, epoxides of Formula 16 are known to the art or can beprepared from compounds known to the art using common reagents andtechniques. For example, Flaugh, et al., J. Med. Chem., 31, 1746 (1988);Nichols et al., Org. Prep. and Proc., Int., 9, 277 (1977); and Leanna etal., Tet. Left., 30, No. 30, 3935 (1989), teach methods of preparationof various embodiments of compounds of structures 16. Those skilled inthe art of organic chemistry will recognize that there are fourstereoisomers of structure 16: ##STR10## Structures 16a and 16b areherein referred to collectively as the exo-isomers; similarly,structures 16c and 16d are the endo-isomers. Leanna et al., supra, teachthe preparation of epoxides of structures 16 which are substantially exoor substantially endo, as desired. The preferred starting material isthe compound of structure 16 wherein Z is benzoyl and X is hydrogen; themost preferred starting material is the mixture of substantially theexo-isomers thereof.

Amino alcohols of structure 18 are formed by reacting an epoxide ofstructure 16 with an amine of formula R¹⁰ NH₂. Such amines are readilyavailable. Opening of the epoxide ring proceeds substantiallyregiospecifically with the amino group at the 5-position and thehydroxyl group at the 4-position. The reaction is also stereospecific inthe sense that stereoisomers of structure 18a-d are formed from,respectively, stereoisomers of structure 16a-d, ##STR11##

A stereoselective synthesis of the amino alcohol of structure 18, andhence of all the subsequent intermediates and products of Scheme 20, canbe effected by using a substantially pure enantiomer of an amine of theformula R¹⁰ NH₂ wherein R¹⁰ contains at least one chiral center. Thediastereomers of the resulting amino alcohol can then be separated by anumber of means known in the art, for example by chromatography orcrystallization. Suitable solvents for recrystallization include thosesuch as diethyl ether, n-butanol, and mixtures of hexane and ethylacetate. An alternative method of achieving a stereospecific synthesisis depicted in Scheme 20 and comprises conversion of all thediastereomers of structure 18 to corresponding diastereomers ofstructure 20, followed by the separation of said diastereomers ofstructure 20; that alternative method is discussed below. If astereoselective synthesis is not desired, then separation of thestereoisomers of the amino alcohol of structure 18 is not required andthe amine R¹⁰ NH₂ need not be optically active.

A particularly efficient stereoselective process for a highly preferredcompound of structure 18,1-benzoyl-4-hydroxy-5-(1-phenylethyl)amino-1,2,2a,3,4,5-hexahydrobenz[cd]indole, comprises the reaction of a mixture ofsubstantially the exo-isomers of the corresponding epoxide of structure16, or a mixture of substantially the endo-isomers of the correspondingepoxide of structure 16, with a substantially pure enantiomer of1-phenethylamine in the solvent n-butanol and the subsequent selectivecrystallization of one of the two isomers of the amino alcohol. Thetemperature of the reaction can be from about 50° to about 150° C.,preferably abut 80° to about 100° C.

After the reaction is complete, as determined for example by thin layerchromatography or liquid chromatography, the desired amino alcohol iscrystallized at about -20° to about 40° C.; the preferred temperaturefor the crystallization is about 0° to about 15° C. Therefore thisprocess has the valuable attribute that the reaction and the separationof stereoisomers occur efficiently in a single step. By the properselection of the epoxide isomers, exo or endo, and the enantiomer of1-phenylethylamine, R or S, one can determine which of the stereoisomersof the compound of structure 18 precipitate from the reaction mixture.

A number of methods of forming aziridines such as those of structure 20from amino alcohols such as those of Formula 18 are known to the art.Two examples are the use of diethyl azodicarboxylate andtriphenylphosphine (O. Mitsunobu, Synthesis, January, 1981, page 1), andthe use of bromine and triphenyl-phosphine (J. P. Freemer and P. J.Mondron, Synthesis, December, 1974, page 894).

A particularly efficient alternative to the above methods involvestreating a compound of structure 18 with a tertiary amine in an inertsolvent followed by the addition of methanesulfonyl chloride. Thefollowing stereoisomers of the aziridine of structure 20, 20a-d, ariserespectively from the stereoisomers of structure 18a-d, with retentionof configuration at any chiral center in the substituents Z, R¹⁰ or X:##STR12## Suitable tertiary amines are those of the formula (R¹¹)₃ N,where the R¹¹ groups are independently C₁ -C₄ alkyl. Suitable solventsare chlorinated hydrocarbons such as methylene chloride, chloroform,carbon tetrachloride, and dichloroethane; aromatic hydrocarbons such asbenzene, toluene, and the xylenes; and ethers such as tetrahydrofuran,diethyl ether, and methyl t-butyl ether. The reaction can be conductedat a temperature from about -35° to about 45° C. In the preferredembodiment, the amino alcohol is treated with triethylamine in methylenechloride at about -20° to about 0° C., then the reaction mixture iswarmed to about 15° to about 35° C. for the completion of the reaction.If desired, the product, an aziridine of structure 20, can becrystallized from an appropriate solvent such as acetonitrile orisopropanol after an aqueous workup. In the event that Z contains atleast one chiral center in substantially a single stereoconfigurationand that the aziridine of structure 20 is prepared as a mixture ofstereoisomers, said stereoisomers can be separated by methods such aschromatography and crystallization, thereby providing a stereospecificsynthesis of the aziridine of structure 20 and subsequent products.

The aziridine ring can be opened to form an intermediate secondary amineof structure 22. A number of methods of opening aziridines are commonlyknown. It is, however, crucial that the method used for opening theaziridine to form a secondary amine of structure 22 be substantiallyregiospecific; the aziridine must be opened to form substantially the4-amino compound rather than the 5-amino compound. One such method iscatalytic hydrogenolysis as taught by Y. Sugi and S. Mitsui, Bull. Chem.Soc. Jap. 43, pp. 1489-1496 (1970). Catalysts which are suitable are theusual hydrogenation and hydrogenolysis catalysts, such as the noblemetal catalysts; the preferred catalyst is palladium. Suitable solventsinclude hydrocarbons such as hexanes and heptanes; aromatic hydrocarbonssuch as benzene, toluene, xylenes, ethylbenzene, and t-butylbenzene;alcohols such as methanol, ethanol, and isopropanol; and mixtures ofsolvents such as acetic acid mixed with said alcohols. The preferredsolvent for preparing the compound of structure 22, wherein Z isbenzoyl, X is hydrogen, and R¹⁰ is 1-phenylethyl, is a mixture oftetrahydrofuran and phosphoric acid or acetic acid. The source ofhydrogen can be an atmosphere of elemental hydrogen supplied at apressure of about 1 atmosphere or higher, or the source of hydrogen canbe compounds which are suitable to serve as hydrogen donors in acatalytic transfer hydrogenolysis reaction, such as formic acid,hydrazine, or cyclohexene. The preferred hydrogen source is anatmosphere of hydrogen gas supplied at about 1 to about 10 atmospherespressure. The temperature of the reaction may be from about -20° toabout 80° C.; the preferred temperature for the hydrogenolysis of theaziridine wherein Z is benzoyl, X is hydrogen, and R¹⁰ is 1-phenylethylis about -20° to about 0° C.

The conversion of compounds of structure 20 to compounds of structure 22proceeds without disturbing the stereochemical configuration of thechiral centers at the 2a- or 4-positions of the structure 22 or of thechiral centers that may be present in any of the substituents.

If desired, the compound of structure 22 can be isolated by the usualmethods such as crystallization. The secondary amine of structure 22 canbe converted to a primary amine of structure 24 by a number of methodsknown to the art of organic chemistry, or alternatively the secondaryamine itself can be isolated.

However, the preferred method is to convert the secondary amine ofstructure 22 to the primary amine of structure 24 without isolating thesecondary amine, but rather by simply continuing without interruptionthe hydrogenolysis reaction that produced the compound of structure 22.Therefore, the preferred solvent and catalyst are the same as those forthe preparation of the secondary amine of structure 22. It may bedesirable to conduct the hydrogenolysis of the secondary amine ofstructure 22 at a different temperature or a different pressure ordifferent temperature and pressure than the hydrogenolysis of theaziridine of structure 20. For the hydrogenolysis of the preferredcompound of structure 22 wherein Z is benzoyl, X is hydrogen, and R¹⁰ is1-phenylethyl, the preferred temperature and pressure are about 50° toabout 60° C. and about 1 to about 20 atmospheres. Under these conditionsthe hydrogenolysis of compounds of structure 22 to compounds ofstructure 24 proceeds without disturbing the stereochemicalconfiguration of the chiral center at the 4-postion.

The isolation of the compound of structure 24 can be accomplished by theusual methods such as crystallization. If desired, the compound ofstructure 24 can be further purified, for example by recrystallization.

Of course, as those skilled in the art will recognize, variations ofScheme 20 will be desirable or necessary for certain embodiments of theinvention. For example, it may be undesirable to subject a compound inwhich X is halo to the catalytic hydrogenolysis steps of Scheme 20because the undesired displacement of the halogen may compete with thedesired hydrogenolysis of the carbon-nitrogen bonds. One alternativestrategy is to postpone the halogenation until after the hydrogenolysis.Another alternative strategy is to use a milder means of reduction thatwould leave the halogen in place. A third alternative, useful in theinstance when the halogen is to serve as a leaving group, is to performthe desired displacement of halogen before the hydrogenolysis step.

Compounds of Formula 1 can be prepared from the compound of structure24, whether it exists as a mixture of stereoisomers or as asubstantially pure enantiomer, using common reagents and methods wellknown in the art. A preferred intermediate to the compounds of theinstant invention is the 6-bromo-derivative. Preferably Z is an aminoblocking group such as benzoyl. A preferred method of introducing thebromo substituent at the 6-position is by reaction with bromine inglacial acetic acid, buffered with sodium acetate. Amino blocking groupscan be added, if desired, to the 4-amino substituent using such methodsas those disclosed by Greene, supra, and Barton, supra. Alkyl groups canbe added, if desired, to the 4-amino substituent using such commonmethods as ammonolysis of the appropriate halide as discussed byMorrison and Boyd, Chapter 22, Organic Chemistry, Third Edition, Allynand Bacon, Boston, 1973, to provide a compound of structure 26 whereinR¹ and R² are defined hereinabove. If desired, the benzoyl group can beremoved from the 1-position using known methods and optionally replacedwith other amino-protecting groups. Preferably the benzoyl grouprepresented by Z is replaced with a triphenylmethyl group prior to themetallating step to form structure 2. The amino-protecting groups andalkyl groups can be added either before or after the bromination, asdesired.

The 4-amino-6-bromohexahydrobenz[cd]indole starting materials used toprepare the compounds of the invention can be readily prepared by otherprocesses such as depicted in Reaction Scheme 2 disclosed in U.S. Pat.No. 4,576,959 of Flaugh, incorporated herein by reference in itsentirety.

The procedure of Scheme 20 using the 4,5-epoxide provides a convenientway to prepare the optically active isomers of the compounds of thepresent invention. Such isomers can also be isolated by resolvingracemic mixtures. This resolution can be carried out in the presence ofa resolving agent, by chromatography or by repeated crystallization.Particularly useful resolving agents are d- and 1-tartaric acids, d- and1-ditoluoyltartaric acids, and the like.

The methods of preparation described in Schemes 2-19 provide compoundsin which the heteroaromatic ring may or may not be substituted. Thegeneral reactions provided below set forth methodology forincorporating, interconverting, and removing substituents on theheteroaromatic ring. Additional methods for performing thesetransformations are cited in Comprehensive Organic Transformations byRichard C. Larock, VCH Publishers, Inc., N.Y. (1989) which isincorporated herein by reference. "HET" refers to the heteroaromaticattached to the hexahydrobenz[cd]indole at position C-6.

    ______________________________________                                        1.  Halogen substituent (X):                                                      HET-OH → HET-X                                                                         POX.sub.3, PX.sub.3, SOX.sub.2, PPh.sub.3 ·                          X.sub.2, or                                                                   P(OR).sub.3 · X.sub.2                                HET-NH.sub.2 → HET-X                                                                   1. HONO; 2. CuX, or KI, or                                                    HBF.sub.4, .increment.                                    2.  O(C.sub.1 -C.sub.3 alkyl), i.e., [OR]                                         HET-X → HET-OR                                                                         RO-, CuI, (DMF, or DMAc, or                                                   NMP), .increment.                                             HET-OH → HET-OR                                                                        Base, RX; or CH.sub.2 N.sub.2                             3.  Hydroxy substituent:                                                          HET-NH.sub.2 → HET-OH                                                                  1. HONO; 2. H.sub.3 O+, .increment.                           HET-OM → HET-OH                                                                        48% HBr, .increment.; or BBr.sub.3                        4.  Cyano substituent:                                                            HET-NH.sub.2 → HET-CN                                                                  1. HONO; 2. CuCN                                              HET-X → HET-CN                                                                         CuCN, (DMF, or DMAc, or NMP), .increment.;                                    or CN.sup.-, .increment.                                  5.  S(C.sub.1 -C.sub.3 alkyl), i.e, [SR]                                          HET-NH.sub.2 → HET-SR                                                                  1. HONO; 2. RSH, base                                         HET-X → HET-SR                                                                         RS.sup.-, CuI, (DMF, or DMAc, or                                              NMP), .increment.                                         6.  Amino substituent:                                                            HET-NO.sub.2 → HET-NH.sub.2                                                            H.sub.2, catalyst (i.e., Pt or Pd)                        7.  Hydrogen substituent:                                                         HET-X → HET-H                                                                          H.sub.2, catalyst; or R.sub.3 SnH, 2,2'-                                      azobis(2-methyl)-                                                             propionitrile), .increment.                                   HET-OH → HET-H                                                                         1. 5-chloro-1-phenyltetrazole,                                                2. H.sub.2, catalyst                                          HET-NH.sub.2 → HET-H                                                                   1. HONO, 2. H.sub.3 PO.sub.2                                  HET-CH.sub.2 Ph → HET-H                                                                H.sub.2, catalyst (i.e., Pd)                                                  (This applies if the benzyl                                                   group is attached to a                                                        nitrogen in the heterocyclic                                                  ring.)                                                        HET-SR → HET-H                                                                         Raney Ni                                                  ______________________________________                                    

6-acyl-substituted-hexahydrobenz[cd]indoles are preferred intermediatesin the preparation of certain of the compounds of the instant invention,particularly 6-isoxazole-indoles and 6-pyrazole-indoles. The 6-acylsubstituted indolines can be prepared by several routes using the6-iodo-substituted indolines of structure 30 as depicted in Scheme 21where R¹, R² and Z are as defined hereinabove. ##STR13##

In a preferred method of preparation as depicted in Scheme 21, thenitrile 32 is contacted with an organometallic reagent such as aGrignard reagent under standard conditions to provide the 6-acylderivative 34. For this reaction Z is preferably benzoyl or trityl.Alternatively, a 6-alkyne intermediate of structure 36 can be preparedand then hydrolyzed to provide the acyl derivative 38. This methodprovides a methylene group adjacent to the carbonyl group. In thismethod Z can be an amino protecting group such as benzoyl although theunprotected 1-nitrogen is preferred, i.e., Z is hydrogen. Compounds ofstructure 30 can be contacted with a palladium catalyst Pd(PPh₃)₄ [wherePh is phenyl] and the tin alkyne compound R¹² --C═C--Sn(CH₃)₃ whereinR¹² is a C₁ -C₇ alkyl, substituted C₁ -C₇ alkyl, aryl (C₁ -C₃ alkyl),substituted aryl (C₁ -C₃ alkyl), or C₃ -C₇ cycloalkyl. This reaction isnormally conducted in a solvent such as toluene at an elevatedtemperature, for example at about 100° C. Typically an excess of the tinalkyne is used along with about 0.25 equivalents of the palladiumcompound based on compound 30. The 6-alkyne 36 is then contacted withHgSO₄ in water to provide the ketone 38.

In another preparation method depicted in Scheme 22, the 6-iododerivative 30 can be used to prepare certain 6-acyl compounds directly.This is accomplished by contacting the 6-iodo compound with atrialkyltinalkyl complex and carbon monoxide in the presence of apalladium catalyst Pd(PPh₃)₄ [where Ph is phenyl] as described in theliterature for arylhalides. [A. Schoenberg and R. F. Heck, J. Org.Chem., 39, p. 3327 (1974); and A. Schoenberg, I. Bartoletti, and R. F.Heck, J. Org. Chem., 39, p. 3318 (1974)]. Although a blocking group Zsuch as diethylcarbamoyl can be used for this method, the method canalso be accomplished when Z is hydrogen, or the blocking group can beremoved to provide compounds of structure 40 where R¹, R² and R¹² are asdefined above. ##STR14##

The following examples further illustrate the preparation of thecompounds of this invention. The examples are provided for purposes ofillustration only and are not to be construed as limiting the scope ofthe instant invention in any way.

The terms and abbreviations used in the instant examples have theirnormal meaning unless otherwise designated, for example, "°C" refers todegrees celsius; "N" refers to normal or normality; "mmol" referes tomillimole; "g" refers to gram; "mL" means milliliter; "M" refers tomolar; "min" refers to minutes; "hr" refers to hours; "NMR" refers tonuclear magnetic resonance; and "MS" refers to mass spectrometry.

EXAMPLE 1

A. Preparation of(±)-1-Benzoyl-6-cyano-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole

To a solution of(±)-1-benzoyl-6-bromo-4-(di-n-propylamino)hexahydrobenz[cd]indole (5.5g, 12.5 mmol) in DMF (100 mL) under a N₂ atmosphere was added 3.4 g(37.5 mmol) of CuCN and 7.1 g (37.5 mmol) of CuI. The reaction mixturewas then stirred at 140° C. for 6 hr. The reaction mixture was pouredonto ice, diluted with water, CH₂ Cl₂ added and stirred for 30 minutes.The mixture was filtered through a Celite pad and the filtrate wasextracted twice with CH₂ Cl₂. The organic solution was washed twice withsaturated NaCl solution. The CH₂ Cl₂ solution was dried over MgSO₄ andthen evaporated to provide 4 g of a solid. Chromatography of this crudeproduct over silica gel with 1:19 MeOH/CH₂ Cl₂ as eluent gave 3 g (62%)of product.

mp=122°-124° C.

B. Preparation of(-)(2aS,4R)-1-Benzoyl-6-cyano-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole

To a solution of (-)(2aS,4R)-6-bromo compound (30.0 g; 0.068 mol) in 500ml of DMF was added CuCN (18.3 g; 0.2 mol) and CuI (38.0 g; 0.2 mol).The reaction mixture was then stirred at 140° C. for 6 hr. The reactionmixture was poured into 4 L of water. The precipitate was collected andwashed several times with water. The precipitate was suspended in diluteNH₄ OH and slurried with ethyl acetate. The whole mixture was filteredthrough a celite pad. The ethyl acetate solution was separated andwashed with brine solution. The ethyl acetate solution was dried (MgSO₄)and concentrated to dryness to provide 21.3 g of the (-)-6-nitrile.

C. Preparation of the (+)(2aR,4S)-6-cyano counterpart of Example 1B.

In a similar manner as in Example 1B above, the (+)(2aR,4S)-6-bromocompound (17.1 g, 0.039 mol) was contacted with CuCN (10.75 g; 0.12 mol)and CuI (22.8 0.12 mol) in 300 ml DMF to give 11.6 g of (+)-6-cyanocompound.

EXAMPLE 2

Preparation of(±)-6-cyano-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole

To a stirred solution of 4.8 g (0.0124 mol) of(±)-1-benzoyl-6-cyano-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indolein 200 mL of THF cooled to -78° C. under a N₂ atmosphere were added 16mL (0.025 mol) of a 1.6M solution of n-butyl lithium in hexane. Thereaction mixture was stirred at -78° C. for 30 minutes and then allowedto warm to -20° C. To the reaction mixture was added 100 mL of 1N HCl.The mixture was extracted once with ethyl ether. The acidic solution wasmade alkaline with the addition of cold 5N NaOH. The basic mixture wasextracted twice with CH₂ Cl₂. The combined organic solution was washedwith a saturated NaCl solution. The CH₂ Cl₂ solution was dried overMgSO₄ and evaporated to give 4 g of an oil. Chromatography of this oilover silica gel with ethyl acetate as eluent gave 3 g (85%) of productas an oil which upon standing solidified.

EXAMPLE 3

Preparation of (+)(2aS,4R)-1-trityl-6-cyano-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole

To a solution of(+)(2aS,4R)-6-cyano-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole(12.8 g, 0.045 mol) and triethylamine (4.5 g, 0.045 mol) in 400 mL ofmethylene chloride was added a solution of triphenylmethyl chloride(trityl chloride) (12.6 g, 0.045 mol) in 100 mL of methylene chloridedropwise at room temperature. The reaction mixture was stirred for 16 hrat room temperature. The reaction mixture was extracted with water andcold 1N HCl. The organic solution was washed with a saturated NaHCO₃solution and with a saturated brine solution. The organic layer wasdried (MgSO₄) and concentrated to dryness in vacuo to give a residue.The residue was slurried with warm hexanes, cooled and filtered toremove insolubles. The filtrate was concentrated to an oil. The oil waschromatographed (silica gel, 20% ethyl acetate in hexanes) to provide20.6 g of the (+)-trityl nitrile.

EXAMPLE 4

Preparation of(+)(2aS,4R)-6-acetyl-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole

A solution of 2.4 g (4.6 mmol) of(+)(2aS,4R)-1-trityl-6-cyano-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole in 100 mL of THF was treated with 25mL of 2.0M methylmagnesium bromide in diethyl ether. The reactionmixture was refluxed for 16 hr. The reaction mixture was cooled andexcess Grignard reagent was decomposed with addition of a saturated NH₄Cl solution. The reaction mixture was extracted with ethyl acetate. Theorganic solution was evaporated to an oil. The oil was dissolved in 25mL of 5N HCl and the solution was stirred at room temperature for 30min. The acidic solution was made alkaline with the addition of excessconcentrated NH₄ OH solution. The basic mixture was extracted twice withethyl acetate. The combined organic solution was washed once with asaturated NaCl solution and dried over MgSO₄. The ethyl acetate solutionwas evaporated to yield 1.4 g of an oil. Chromatography of this oil oversilica gel with ethyl acetate as eluent gave 1.2 g (87%) of product.Recrystallization from hexanes yielded 840 mg of the product (+) ketone.

mp=121°-122° C.

[α]_(D) +67.40° (MeOH).

EXAMPLE 5

Preparation of(±)-6-acetyl-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole

A solution of 0.5 g (1.8 mmol) of(±)-6-cyano-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]in 75 mLof benzene was treated with 5 mL of 2.0M methylmagnesium bromide indiethyl ether. The reaction mixture was refluxed for 2 days. Thereaction mixture was cooled and excess Grignard reagent was decomposedwith addition of a saturated NH₄ Cl solution. The benzene layer wasseparated and washed once with a saturated NaCl solution. The organicsolution was evaporated to an oil. The oil was dissolved in 25 mL of 5NHCl and the solution was stirred at room temperature for 30 min. Theacidic solution was made alkaline with the addition of excessconcentrated NH₄ OH solution. The basic mixture was extracted twice withCH₂ Cl₂. The combined organic solution was washed once with a saturatedNaCl solution and dried over MgSO₄. The CH₂ Cl₂ solution was evaporatedto yield 0.5 g of an oil. Chromatography of this oil over silica gelwith ethyl acetate as eluent gave 0.4 g (75%) of product as an oil whichupon standing solidified.

mp=76°-77° C.

EXAMPLE 6

Preparation of (+)(2aS,4R)-6-(3-pyrazolyl)-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole·2HCL

A solution of (+)(2aS,4R)-1-triphenylmethyl-6-acetyl-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole (1.67 g, 3 mmol) and 3 mL oftris(dimethylamino)methane in 50 mL of toluene was refluxed for 5 hr.The reaction was concentrated in vacuo and the residue was dissolved in100 mL of CH₃ OH. To the CH₃ OH solution was added 2 mL of 85% hydrazineand the reaction mixture was stirred at room temperature for 16 hours.To the reaction mixture was added 50 ml of 1N HCl and stirred for anadditional 1 hr. The solution was concentrated in vacuo to remove CH₃ OHand the acidic solution was extracted with ethyl acetate. The acidicsolution was separated and made alkaline with addition of excessconcentrated NH₄ OH. The basic mixture was extracted with ethyl acetate.The ethyl acetate solution was washed with a brine solution, dried(MgSO₄) and concentrated in vacuo to provide 900 mg of an oil. The crudeproduct was chromatographed through silica gel (flash column, ethylacetate) to yield 700 mg of pyrazole compound. The oil was dissolved in50 mL of CH₃ OH and 2 equivalents of 0.1N HCL was added to the solution.The solution was concentrated in vacuo and the residue was crystallizedfrom ethanol/diethyl ether.

Yield--400 mg

mp=260 d

MS m/e 324(FD)

[α]_(D) +19.84° (MeOH).

Analysis calculated for C₂₀ H₂₈ N.sub. ·2HCl

Theory: C, 60.45; H, 7.61; N, 14.10;

Found: C, 60.21; H, 7.60; N, 14.26.

EXAMPLE 7

Preparation of (±)-6-(5-isoxazolyl)-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole·2HCl

To a solution of(±)-6-acetyl-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole(2.3 g, 7.7 mmol) and triethylamine (1.1 ml, 8 mmol) in 90 ml CH₂ Cl₂under N₂ was added dropwise a solution of 2,2,2-trichloroethylchloroformate. The reaction mixture was stirred at room temperature for1 hr. The CH₂ Cl₂ solution was extracted with water and 1N HCl. Theorganic solution was washed with a saturated NaHCO₃ solution and with abrine solution. The CH₂ Cl₂ solution was dried (MgSO₄) and concentratedin vacuo to give 3.3 g of the 1-carbamylindoline.

A solution of this 1-carbamylindoline (3.3 g, 7.7 mmol) andtris(dimethylamino)methane (5 mL) in 70 mL of toluene was stirred atreflux for 16 hr. The reaction mixture was concentrated to dryness invacuo. The residue was dissolved in 50 mL of acetic acid andhydroxylamine hydrochloride (2.5 g, 36 mmol) was added. The reactionmixture was stirred at room temperature for 16 hr and then concentratedin vacuo to dryness. The residue was suspended in water and excessconcentrated NH₄ OH was added to the mixture. The basic mixture wasextracted with CH₂ Cl₂. The organic solution was washed with a brinesolution, dried (MgSO₄) and concentrated in vacuo to give 3.1 g of anoil. The crude product was chromatographed (flash column, silica gel,20% hexanes in ethyl acetate) to yield 2.0 g of(±)-1-carbamyl-6-isoxazolylindoline.

This isoxazole carbamate was dissolved in 20 mL of acetic acid and 1 gof zinc dust was added all at once. The reaction mixture was stirred atroom temperature for 4 hr. The reaction mixture was filtered through acelite pad and the filtrate was concentrated to dryness in vacuo. Theresidue was suspended in a saturated NaHCO₃ solution and extracted withCH₂ Cl₂. The organic solution was washed with a brine solution, dried(MgSO₄) and concentrated to an oil. The crude material waschromatographed (flash column, silica gel, ethyl acetate) to give 500 mgof isoxazole indoline. The product was dissolved in 50 mL of CH₃ OH and2 equivalents of 0.1N HCl were added. The solution was concentrated todryness and the residue was crystallized from ethanol/diethyl ether togive 85 mg of isoxazole substituted product as the dihydrochloride.

mp=226° C. d

MS m/e 325(FD)

Analysis calculated for C₂₀ H₂₇ N₃ O·2HCl

Theory: C, 60.30; H, 7.34; N, 10.55;

Found: C, 58.83; H, 7.18; N, 10.01.

EXAMPLE 8

Preparation of(+)(2aS,4R)-6-(3-isoxazolyl)-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole·2HCl

A solution of(+)(2aS,4R)-1-triphenylmethyl-6-acetyl-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole (3.33 g, 6 mmol), 5 g hydroxylaminehydrochloride, 20 mL pyridine and 30 mL of ethanol was refluxed for 16hr. The reaction mixture was concentrated to dryness in vacuo and theresidue was dissolved in 5N HCl. The acidic mixture was extracted withethyl acetate. The acidic solution was made alkaline with excess NH₄ OHsolution and extracted with ethyl acetate. The ethyl acetate solutionwas washed with a brine solution, dried (MgSO₄) and concentrated invacuo to give 1.5 g of crude product which was chromatographed (flashcolumn, silica gel, ethyl acetate) to give 1.2 g of oxime.

mp=129°-130° C.

To a solution of this oxime (1.2 g, 3.8 mmol) in 100 mL of THF cooled to-5° C. under a N₂ atmosphere was added 7.5 mL n-butyllithium (1.6M inhexanes) dropwise with stirring. The reaction mixture was stirred withcontinued cooling for 1 hr. To the reaction mixture was added 2 mL (26mmol) of DMF all at once and then stirred for 1 hr at room temperature.The reaction mixture was poured into 50 mL of 1N H₂ SO₄ and the acidicsolution was warmed on a steam bath for 1 hr. The acidic solution wascooled, extracted with diethyl ether, and then made alkaline with excess5N NaOH. The basic mixture was extracted with ethyl acetate. The organicwas layer was washed with a brine solution, dried (MgSO₄) andconcentrated in vacuo to give 1 g of an oil. The oil was chromatographed(flash column, silica gel, ethyl acetate) to yield 500 mg of product asan oil. The oil was dissolved in 50 mL of CH₃ OH and 2 equivalents of0.1N HCL were added. The solution was concentrated to dryness in vacuoand the residue was crystallized from ethanol/diethyl ether.Crystallization gave 300 mg of the dihydrochloride of the6-(3-isoxazolyl) product.

mp=215° C. d

MS m/e 325(FD)

[α]_(D) +26.4° (MeOH).

EXAMPLE 9

Preparation of(±)-1-benzoyl-6-[4-(2-amino-thiazolyl)]-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole

To a solution of(±)-6-acetyl-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole(205 mg, 0.7 mmol) and triethylamine (81 mg, 0.8 mmol) in 20 mL of CH₂Cl₂ was added a solution of benzoyl chloride (112 mg, 0.8 mmol) in 20 mLof CH₂ Cl₂. The reaction mixture was stirred at room temperature for 2hr. The reaction mixture was sucessively washed with water, a saturatedNaHCO₃ solution, a brine solution and dried (MgSO₄). The organic layerwas concentrated to dryness in vacuo to give 200 mg of the 1-benzoylderivative.

A solution of this N-benzoyl compound (200 mg, 0.5 mmol) in 20 mL ofacetic acid was saturated with HBr (gas). To the solution was addeddropwise a solution of bromine (0.2 mL) in 5 mL of acetic acid. Thereaction was stirred at room temperature for 30 min and thenconcentrated to dryness an vacuo. The residue was dissolved in 30 mL ofethanol then 500 mg of thiourea were added and the mixture refluxed for16 hr. The reaction was concentrated to dryness an vacuo and the residuedissolved in water. The solution was made alkaline with the addition ofconcentrated NH₄ OH. The basic mixture was extracted with CH₂ Cl₂. Theorganic solution was washed with a brine solution, dried (MgSO₄) andevaporated to dryness to give 200 mg of an oil. The oil waschromatographed (flash column, silica gel, ethyl acetate) to provide 140mg of the above-named 6-aminothiazolyl compound.

MS m/e 460(FD)

EXAMPLE 10

Preparation of(+)(2aS,4R)-6-(5-isoxazolyl)-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole·2HCl

To a solution of (+)(2aS,4R)-6-acetyl-4-(di-n-5 propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole (1.7 g, 5.7 mmol) and triethylamine (0.8 ml,6 mmol) in 90 ml CH₂ Cl₂ was added dropwise a solution of2,2,2-trichloroethyl chloroformate (1.3 g, 6 mmol) in 10 ml CH₂ Cl₂. Thereaction mixture was stirred at room temperature for one hour and thenextracted with water and 1N HCl. The organic solution was washed with asaturated NaHCO₃ solution, a saturated brine solution, dried over MgSO₄and then concentrated to dryness in vacuo to give 2.5 g of the1-carbamylindoline.

A solution of the 1-carbamylindoline (2.5 g, 5.7 mmol) andtris(dimethylamino)methane (5 ml) in 100 ml of toluene was stirred atreflux for 16 hours. After 16 hours the reaction mixture wasconcentrated to dryness in vacuo. The resulting residue was dissolved in50 ml of acetic acid and 1.5 g (22 mmol) of a hydroxylaminehydrochloride solution were added. The resulting reaction mixture wasstirred at room temperature for 16 hours and then concentrated todryness in vacuo. The resulting residue was suspended in water and anexcess of a concentrated NH₄ OH solution was added to the mixture. Thebasic mixture was then extracted with CH₂ Cl₂ and the resulting organicextract was washed with a saturated brine solution, dried over MgSO₄ andthen concentrated in vacuo to give 2.1 g of an oil. This oil waschromatographed (flash column, silica gel, EtOAc) to yield 1.9 g of(+)(2aS,4R)-6-(5-isoxazolyl)indoline. The isoxazolylindoline wasdissolved in 30 ml of acetic acid and 1.5 g of zinc dust were added allat once. The resulting reaction mixture was stirred at room temperaturefor four hours and then filtered through a celite pad. The filtrate thusobtained was then concentrated to dryness in vacuo. The resultingresidue was suspended in a saturated NaHCO₃ solution, which was thenextracted with CH₂ Cl₂. The organic extract was then washed with asaturated brine solution, dried over MgSO₄ and concentrated in vacuo toan oil. This oil was chromatographed (flash column, silica gel, EtOAc)to give 400 mg of isoxazolylindoline. Such compound was dissolved in 50ml of methanol and two equivalents of 0.1N HCl were added. The resultingsolution was concentrated to dryness in vacuo and the resulting residuewas then crystallized from ethanol/diethyl ether to give 170 mg of titlecompound.

mp=235° C. d

MS m/e 325 (FD)

[α]_(D) +27.29° (MeOH)

Analysis calculated for C₂₀ H₂₇ N₃ O·2HCl

Theory: C, 60.30; H, 7.34; N, 10.55;

Found: C, 60.53; H, 7.54; N, 10.26.

EXAMPLE 11

Preparation of(-)(2aR,4S)-6-(5-isoxazolyl)-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole·2 HCl

The title compound was prepared substantially in accordance with themethod described in Example 10, above, utilizing 2.5 g (8.3 mmol) of(-)(2aR,4S)-6-acetyl-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole (prepared substantially in accordance withthe method described in Example 4) and 1.5 g (22 mmol) of ahydroxylamine hydrochloride solution. Such reaction sequence provided500 mg of title compound.

m.p. 235° C. d

MS m/e 325 (FD)

[α]_(D) -29.18° (MeOH)

Analysis calculated for C₂₀ H₂₇ N₃ O·2HCl

Theory: C, 60.30; H, 7.34; N, 10.55;

Found: C, 60.11; H, 7.41; N, 10.43.

EXAMPLE 12

Preparation of(2aR,4S)-6-(3-phenyl-1,2,4-oxadiazol-5-yl)-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole

A sodium ethoxide solution was prepared by dissolving 49 mg (2.1 mmol)of sodium in 35 ml of ethanol. Phenylhydroxamidine (1.73 g, 12.71 mmol)and 6-ethoxycarbonyl-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole (890 mg, 2.1 mmol) were added to the ethoxidesolution and the resulting solution was heated to reflux and stirred atthat temperature for 6.25 hours and then stirred overnight at roomtemperature. The next morning additional sodium ethoxide solution (50 mgof sodium in 10 ml of ethanol) was added and the reaction mixture wasagain stirred at reflux overnight. The next morning water was added tothe reaction mixture and the resulting solution was then extracted withethyl acetate. The organic extract was washed sequentially with waterand a saturated brine solution, dried over sodium sulfate and thenconcentrated in vacuo to provide 2.33 g of a brown oil. This oil waspurified by flash chromatography (2.5% isopropanol in chloroform plus0.5% ammonium hydroxide) to provide 260 mg of title product as a lightyellow solid. Such product was purified by recrystallization fromhexane.

Analysis calculated for C₂₅ H₃₀ N₄ O

Theory: C, 74.59; H, 7.51; N, 13.92;

Found: C, 74.59; H, 7.52; N, 13.90.

EXAMPLE 13

Preparation of (-)(2aR,4S)-6-(2-furyl)-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole

To a sealable tube with threads containing 13 ml of dry tetrahydrofuranwere added 1.2 g (2.46 mmol) of(+)(2aR,4S)-1-benzoyl-6-iodo-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole,968 mg (2.71 mmol) of 2-(tributylstannyl)furan and 200 mg ofbis(triphenylphosphine)palladium(II) chloride. The resulting mixture wasthen deaerated with argon for 15 minutes. After deaeration, the tube wassealed with a teflon cap and the contents thereof were heated to 100° C.for 24 hours. After 24 hours, the reaction mixture was cooled, filteredthrough a celite pad and the resulting filtrate was then concentrated invacuo to provide a viscous orange oil. Flash chromatography of this oilover silica gel with 60% ethyl acetate/hexane plus 0.5% ammoniumhydroxide as eluent gave the protected analog of the title compound in61% yield.

The above-mentioned protected analog (635 mg, 1.4 mmol) was dissolved in10 ml of dry tetrahydrofuran and the resulting solution was chilled to-78° C. Once chilled, 1.5 ml (2.39 mmol) of a 1.7M solution ofn-butyllithium in hexane was added dropwise via syringe. Oncen-butyllithium addition was complete the reaction mixture was warmed toroom temperature. The reaction mixture was quenched with a saturatedNaHCO₃ solution and then partitioned between ethyl acetate and water.The aqueous layer was extracted with ethyl acetate, and the organiclayers were combined, washed with a saturated brine solution, dried oversodium sulfate and then concentrated in vacuo to provide a viscousorange oil. This oil was chromatographed over silica gel (elution with20% ethyl acetate/hexane plus 0.5% ammonium hydroxide) to provide 161 mgof title compound as a pale yellow oil.

MS m/e 324(FD)

[α]_(D) -45.63° (MeOH)

Analysis calculated for C₂₁ H₂₈ N₂ O:

Theory: C, 77.74; H, 8.70; N, 8.63;

Found: C, 78.74; H, 8.82; N, 8.27.

EXAMPLE 14

Preparation of (+)(2aS,4R)-6-(2-furyl)-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole

The title compound was prepared substantially in accordance with themethod set forth in Example 13, above, utilizing 1.5 g (3.07 mmol) of(-)(2aS,4R)-1-benzoyl-6-iodo-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole, 250 mg ofbis(triphenylphosphine)palladium(II) chloride and 1.21 g (3.38 mmol) of2-(tributylstannyl)furan to provide 592 mg of title compound as aviscous brown oil.

MS m/e 325.22(FD)

[α]_(D) +42.0° (MeOH)

Analysis calculated for C₂₁ H₂₈ N₂ O:

Theory: C, 77.74; H, 8.70; N, 8.63;

Found: C, 77.59; H, 8.10; N, 8.83.

EXAMPLE 15

Preparation of (+) (2aS,4R)-6-(3-furyl)-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole

The title compound was prepared substantially in accordance with themethod described in Example 13, above, utilizing 1.50 g (3.07 mmol) of(+)(2aS,4R)-1-benzoyl-6-iodo-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole, 1.21 g (3.38 mmol) of3-(tributylstannyl)furan and 250 mg of bis(triphenylphosphine)palladium(II) chloride to provide 711 mg of titleproduct as a pale yellow viscous oil.

MS m/e 324 (FD)

Analysis calculated for C₂₁ H₂₈ N₂ O:

Theory: C, 77.24; H, 8.70; N, 8.63;

Found: C, 77.49; H, 8.68; N, 8.45.

EXAMPLE 16

Preparation of(+)(2aS,4R)-6-(2-thienyl)-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole

The title compound was prepared substantially in accordance with themethod set forth in Example 13, above, utilizing 1.5 g (3.1 mmol) of(-)(2aS,4R)-1-benzoyl-6-iodo-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole, 150 mg ofbis(triphenylphosphine)palladium(II) chloride and 1.27 g (3.41 mmol) of2-(tributylstannyl)thiophene to provide 719 mg of title compound as alight brown viscous oil.

MS m/e 341(FD)

Analysis calculated for C₂₁ H₂₈ N₂ S:

Theory: C, 74.07; H, 8.29; N, 18.60; S, 9.42;

Found: C, 74.24; H, 8.60; N, 17.52; S, 9.15.

EXAMPLE 17

Preparation of (+)(2aS,4R)-6-(2-pyridyl)-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole

The title compound was prepared substantially in accordance with themethod set forth in Example 13, above, utilizing 1.50 g (3.07 mmol) of(-)(2aS,4R)-1-benzoyl-6-iodo-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole, 250 mg ofbis(triphenylphosphine)palladium(II) chloride and 1.24 g (3.38 mmol) of2-(tributylstannyl)pyridine to produce 474 mg of title compound as acolorless foam. The hydrochloride salt of the title compound wasprepared by dissolving the foam in diethyl ether and then treating theresulting solution with a saturated hydrochloric acid in methanolsolution. A yellow foam comprised of such salt was afforded afterconcentration in vacuo.

MS m/e 336.24(FD)

Analysis calculated for C₂₂ H₂₉ N₃ ·HCl

Theory: C, 71.04; H, 8.13; N, 11.30;

Found: C, 70.60; H, 8.46; N, 10.58.

EXAMPLE 18

Preparation of (+)(2aS,4R)-6-(3-pyridyl)-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole

The title compound was prepared substantially in accordance with theprocedure set forth in Example 13, above, utilizing 1.50 g (3.07 mmol)of (-)(2aS,4R)-1-benzoyl-6-iodo-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole, 250 mg ofbis(triphenylphosphine)palladium(II) chloride and 1.24 g (3.38 mmol) of3-(tributylstannyl)pyridine to produce 475 mg of title compound as apale yellow oil. The dihydrochloride salt of the title compound wasprepared by dissolving the oil in diethyl ether and then adding asaturated hydrochloric acid in methanol solution dropwise. Once anexcess of hydrochloric acid had been added the mixture was concentratedin vacuo to provide a pale yellow foam.

MS m/e 336.24(FD)

Analysis calculated for C₂₂ H₂₉ N₃ ·2HCl:

Theory: C, 64.70; H, 7.65; N, 10.29;

Found: C, 65.84; H, 7.55; N, 9.76.

EXAMPLE 19

Preparation of (-)(2aR,4S)-6-(2-oxazolyl)-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole

A. 2-tributylstannyloxazole

A solution of 1.00 g (14.5 mmol) of oxazole in 25 ml of THF at -78° C.was treated with 10.2 ml (14.6 mmol) of 1.43M butyllithium in hexane.After stirring for 30 minutes, an addition of 3.93 ml (14.5 mmol) oftributyltin chloride was made, and the solution was allowed to warm toroom temperature. Stirring was continued for another hour after whichmost of the solvents were evaporated in vacuo. The resulting residue wastaken up in 50 ml of hexane, and the resulting precipitate was separatedby filtration through filtercel. Evaporation of the solvent from thefiltrate provided 5.13 g of a colorless oil which was identified by NMRas the 2-stannyl derivative plus a small amount of tetrabutylstannane.

B. (2aR,4S)-1-benzoyl-6-(2-oxazolyl)-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole

A solution of 5.0 g (13.8 mmol) of the crude 2-tributylstannyloxazoleprepared above and 6.8 g (13.9 mmol) of(+)(2aR,4S)-1-benzoyl-6-iodo-4-(di-n-propylamino)-1,2,2a, 3,4,5-hexahydrobenz[cd]indole in 100 ml of toluene was treated with 0.7 g(0.6 mmol) of tetrakis(triphenylphosphine)palladium then refluxed undernitrogen for 20 hours. After cooling the reaction mixture was washedwith a saturated brine solution and then dried over Na₂ SO₄.Concentration in vacuo provided a viscous oil which was chromatographedover a silica gel column using a solvent gradient progressing fromtoluene to 1:1 toluene/EtOAc. The product from the column was dissolvedin 1M HCl. This solution was then washed with ether, made alkaline with5M NaOH, and extracted with CH₂ Cl₂. Concentration of the extract invacuo gave about 4 g of a brown oil. When this oil was dissolved inpentane a small amount of a red/brown resin separated leaving a clear,yellow solution. The resin was separated and the pentane was evaporatedto provide a residue. This residue was crystallized by dissolving it ina small amount of CH₂ Cl₂ and slowly adding isoctane. The crystalline(-)(2aR,4S)-1-benzoyl-6-(2-oxazolyl)-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole, obtained in four crops, weighed 2.63 g. mp103°-104° C.

C.(-)(2aR,4S)-6-(2-oxazolyl)-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole

A solution of 1.00 g (2.33 mmol) of the above 1-benzoyl compound in 25ml of THF was stirred at -78° C. as 3.0 ml (4.29 mmol) of 1.43Mbutyllithium in hexane was added. The resulting solution was allowed towarm to 0° C., then poured into water and extracted with CH₂ Cl₂. TheCH₂ Cl₂ extract was then, in turn, extracted with 1M HCl. The resultingaqueous extract was made alkaline with 1M NaOH, and, in turn, extractedwith CH₂ Cl₂. After drying over Na₂ SO₄, the extract was concentrated invacuo to provide title compound as a viscous oil. m.p. 103°-104° C.

MS m/e 326(FD)

[α]_(D) =-60° (MeOH).

Analysis calculated for C₂₀ H₂₇ N₃ O:

Theory: C, 73.81; H, 8.36; N, 12.91;

Found: C, 73.37; H, 8.26; N, 12.09.

EXAMPLE 20

Preparation of(-)(2aR,4S)-6-(5-isoxazolyl)-4-[di-(cyclopropylmethyl)amino]-1,2,2a,3,4,5-hexahydrobenz[cd]indole

To a solution of(-)(2aR,4S)-6-acetyl-4-[di-(cyclopropylmethyl)amino]-1,2,2a,3,4,5-hexahydrobenz[cd]indole (2.5 g, 7.7 mmol) and triethylamine (1.1 ml, 8mmol) in 90 ml CH₂ Cl₂ was added dropwise a solution of2,2,2-trichloroethylchloroformate (1.7 g, 8 mmol) in 10 ml CH₂ Cl₂. Thereaction mixture was stirred at room temperature for one hour and thenextracted with water and 1N HCl. The organic solution was washed with asaturated NaHCO₃ solution and a saturated brine solution, dried overMgSO₄ and then concentrated to dryness in vacuo to give 3.1 g of the1-carbamylindoline.

A solution of the 1-carbamylindoline (3.1 g, 6.2 mmol) andtris(dimethylamino)methane (5 ml) in 100 ml of toluene was stirred atreflux for 16 hours. After 16 hours the reaction mixture wasconcentrated to dryness in vacuo. The resulting residue was dissolved in50 ml of acetic acid and 2.0 g (29 mmol) of a hydroxylaminehydrochloride solution were added. The resulting reaction mixture wasstirred at room temperature for 16 hours and then concentrated todryness in vacuo. The resulting residue was suspended in water and anexcess of a concentrated NH₄ OH solution was added to basify themixture. The basic mixture was then extracted with CH2C12 and theresulting organic extract was washed with a saturated brine solution,dried over MgSO₄ and then concentrated in vacuo to give 2.1 g of an oil.This oil was chromatographed (flash column, silica gel, EtOAc) to yield1.7 g of the protected (+) (2aR,4S)-6-(5-isoxazolyl)indoline.

The above compound (1.7 g, 3.2 mmol) was dissolved in 30 ml of aceticacid and 1.5 g of zinc dust were added all at once. The resultingreaction mixture was stirred at room temperature for four hours and thenfiltered through a celite pad. The filtrate thus obtained was thenconcentrated to dryness in vacuo. The resulting residue was suspended ina saturated NaHCO₃ solution, then extracted with CH₂ Cl₂. The organicextract was then washed with a saturated brine solution, dried overMgSO₄ and concentrated in vacuo to an oil. This oil was chromatographed(flash column, silica gel, EtOAc) to give 660 mg of title compound.

EXAMPLE 21

Preparation of(-)(2aR,4S)-6-(5-oxazolyl)-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole

A. (-)(2aR,4S)-6-bromo-1-trityl-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole

To a stirred solution of 12.8 g (29 mmol) of(+)(2aR,4S)-1-benzoyl-6-bromo-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indolein 200 ml of tetrahydrofuran cooled to -78° C. under a nitrogenatmosphere was added 20 ml (32 mmol) of a 1.6M solution ofn-butyllithium in hexane. The reaction mixture was stirred at -78° C.for 30 minutes and then allowed to warm to -20° C. To the reactionmixture was added 50 ml of a 1N hydrochloric acid solution. The mixturewas extracted once with diethyl ether. The acidic solution was madealkaline with the addition of cold 5N sodium hydroxide solution. Thebasic mixture was extracted twice with methylene chloride. The combinedorganic solution was washed with a saturated sodium chloride solution.The methylene chloride solution was dried over magnesium sulfate andevaporated to give 9.6 g of(-)(2aR,4S)-6-bromo-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole.

To a solution of the above product (9.6 g, 0.028 mol) and triethylamine(3.03 g, 0.03 mol) in 100 ml of methylene chloride was added a solutionof trityl chloride (7.8 g, 0.028 mol) in 100 ml of methylene chloridedropwise at room temperature. The reaction mixture was stirred for 16hours at room temperature. The reaction mixture was extracted with waterand a cold 1N hydrochloric acid solution. The organic solution waswashed with a saturated sodium bicarbonate solution and with a saturatedbrine solution. The organic solution was dried over magnesium sulfateand concentrated to dryness in vacuo to give a residue. The residue wasslurried with warm hexane, cooled and filtered to remove insolubles. Thefiltrate was concentrated to an oil. The oil was chromatographed (silicagel, 20% ethyl acetate in hexane) to provide 12.7 g of the above-titledcompound.

B.(-)(2aR,4S)-6-formyl-1-trityl-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole

To a solution of(-)(2aR,4S)-6-bromo-1-trityl-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole (6.8 g, 12 mmol) in 100 ml of tetrahydrofurancooled to -78° C. under a nitrogen atmosphere was added dropwise a 1.6Msolution of n-butyllithium in hexane. The reaction mixture was stirredat -78° C. for 1 hour. Dimethylformamide (3 ml) was added to thereaction mixture and the mixture was stirred at room temperature for 30minutes. The reaction mixture was quenched with water and then extractedwith ethyl acetate. The ethyl acetate solution was washed with asaturated brine solution, dried over magnesium sulfate and concentratedto dryness to provide 5.6 g of the above-titled compound as an oil.

C.(-)(2aR,4S)-6-(5-oxazolyl)-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole

A reaction mixture of(-)(2aR,4S)-6-formyl-1-trityl-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole (1.06 g, 2 mmol), tosylmethyl isocyanide (390mg, 2 mmol) and potassium carbonate (304 mg, 2.2 mmol) in 100 ml ofmethanol was stirred at reflux temperature under a nitrogen atomospherefor 16 hours. The reaction mixture was concentrated to dryness and waterwas added to the residue. The aqueous mixture was extracted with ethylacetate. The ethyl acetate solution was washed with a saturated brinesolution, dried over magnesium sulfate and concentrated to dryness toyield 1 g of an oil. The oil was dissolved in 20 ml of tetrahydrofuran,and 50 ml of 5N hydrochloric acid solution. The reaction mixture wasstirred at room temperature for 30 minutes. The reaction mixture wasextracted twice with ethyl acetate and the acidic solution was then madealkaline by addition of excess concentrated ammonium hydroxide solution.The basic mixture was extracted twice with ethyl acetate. The ethylacetate solution was washed with a saturated brine solution, dried overmagnesium sulfate and concentrated to dryness to provide 0.5 g of anoil. The oil was purified by silica gel chromatography, with ethylacetate as eluent, to give 0.3 g of title compound.

MS (FD) m/e/325

EXAMPLE 22

Preparation of (2aR,4S)-6-(3-pyridyl)-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole

A. 3-pyridylboronic acid

A solution of 4.0 ml (6.56 g, 42 mmol) of 3-bromopyridine and 9 ml (8mmol) of trimethylborate in 100 ml of diethyl ether was cooled to -70°C. then treated slowly with 33 ml (83.8 mmol) of a 2.54Mtert-butyllithium in pentane solution. After allowing the resultingslurry to warm to room temperature the solvents were evaporated undervacuum. The residual oil was treated carefully with 50 ml of a 1Mhydrochloric acid solution. Several milliters of methylene chloride wereadded and the mixture was stirred until the oil had dissolved. Theaqueous layer was washed with fresh methylene chloride. The pH of theaqueous solution was raised to 12 with 5M sodium hydroxide solution andthe washing was repeated. The pH of the aqueous solution was thenlowered to 6.5 with concentrated hydrochloric acid solution. Afterchilling, this solution was filtered, saturated with sodium chloride,then extracted several times with a 2:1 mixture of diethyl ether andisopropanol. Evaporation of these extracts produced a colorless solid.This material was further purified by dissolving in methanol,evaporating to a thick paste, adding a few milliters of water,concentrating further under vacuum, then chilling and collecting thecrystalline product. Additional product in the aqueous mother liquor wasisolated by repeating this process. Thorough drying of this hydratedproduct at 0.1 mm pressure afforded a fine powder weighing 2.2 g.Elemental analysis and a mass spectrum indicated the product so isolatedwas primarily the anhydride (tripyridylboroxane).

B. (2aR,4S)-1-benzoyl-6-(3-pyridyl)-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole

A solution of 4.00 g of(2aS,4R)-1-benzoyl-6-iodo-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole and 0.60 g (0.525 mmol) oftetrakis(triphenylphosphine)palladium in 50 ml of toluene was combinedwith 10 ml of a 2M sodium bicarbonate solution. This mixture was treatedwith 1.1 g (9.0 mmol) of the above 3-pyridylboronic anhydride, and itwas stirred vigorously at 105° C. under nitrogen for 24 hours. Thehalf-complete reaction was charged with an additional 1.0 g of3-pyridylboronic anhydride and heating was continued another 24 hours.The cooled mixture was filtered through filtercel. The organic layer waswashed with a saturated sodium chloride solution. The toluene wasevaporated and the residue was partitioned between 1M hydrochloric acidsolution and methylene chloride. The aqueous layer was basified with 5Msodium hydroxide solution and the product was extracted into methylenechloride. After washing with a saturated sodium chloride solution anddrying over sodium sulfate the methylene chloride was evaporated leavinga viscous oil. This crude product was chromatographed over a silica gelcolumn using 10% ethyl acetate in toluene, then 25% ethyl acetate intoluene, and finally 1:1 ethyl acetate/toluene as eluent. The purified(2aR,4S)-1-benzoyl-6-(3-pyridyl)-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole was an oil weighing 2.99 g.

C. (2aR,4S)-6-(3-pyridyl)-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indol

A solution of 2.75 g (6.26 mmol) of the above 1-benzoyl compound in 50ml of tetrahydrofuran was stirred at -78° C. as 7.7 ml (11.3 mmol) of a1.47M butyllithium in hexane solution was added. This solution wasallowed to warm to 0° C., then poured into water and extracted withmethylene chloride. The methylene chloride was evaporated and theresidue was chromatographed over 50 g of florisil using ethyl acetate aseluent. The product from the column was a pale yellow oil weighing 2.0 gwhich assayed as title product.

EXAMPLE 23

Preparation of(-)(2aR,4S)-6-(3-isoxazolyl)-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole

To a cool (-5° C.) solution of 2.6 g (3.6 mmol) of (-)(2aR,4S)-1-triphenylmethyl-6-(1-oximidoethane)-4-(di-n-propylamino)-1,2,2a,3,4,5-hexahydrobenz[cd]indole (prepared substantially in accordance with theoxime substrate prepared in Example 8) in 100 ml of tetrahydrofuran wasadded 6.9 ml of a 1.6M solution of n-butyllithium in hexane. Theresulting solution was stirred at -5° C. for one hour and then 2 ml (26mmol) of dimethylformamide was added all at once. The resulting solutionwas warmed to room temperature and then stirred for one more hour. Afterstirring at room temperature for one hour, the reaction solution waspoured into 50 ml of a 1N sulfuric acid solution. The acidic solutionwas warmed on a steam bath for one hour, cooled to room temperature andthen extracted with diethyl ether to remove impurities. The acidicsolution was made alkaline with excess 5N sodium hydroxide solution andthen extracted with ethyl acetate. The extract was washed with asaturated brine solution, dried over magnesium sulfate and thenconcentrated in vacuo to provide 1 g of an oil. This oil was purified byflash chromatography (using ethyl acetate as eluent) to provide 400 mgof the title compound as an oil.

The present compounds of Formula 1 have been found to have selectiveaffinity for the 5HT receptors in the brain with much less affinity forother receptors. Because of their ability to selectively bind to 5HTreceptors, the compounds of Formula 1 are useful in treating diseasestates which require alteration of 5-HT receptor function, particularly5-HT_(1A), and/or 5HT_(1D) but without the side effects which may beassociated with less selective compounds. This alteration may involvereproducing (an agonist) or inhibiting (an antagonist) the function ofserotonin. These disease states include anxiety, depression, excessivegastric acid secretion, motion sickness, hypertension, nausea andvomiting, sexual dysfunction, cognition, senile dementia, migraine,consumptive disorders such as appetite disorders, alcoholism andsmoking. The foregoing conditions are treated with a pharmaceuticallyeffective amount of a compound of Formula 1 or a pharmaceuticallyacceptable salt thereof.

The term "pharmaceutically effective amount", as used herein, representsan amount of a compound of the invention which is capable of diminishingthe adverse symptoms of the particular disease. The particular dose ofcompound administered according to this invention shall, of course, bedetermined by the particular circumstances surrounding the case,including the compound administered, the route of administration, theparticular condition being treated, and similar considerations. Thecompounds can be administered by a variety of routes including the oral,rectal, transdermal, subcutaneous, intravenous, intramuscular orintranasal routes. A typical single dose for prophylactic treatment,however, will contain from about 0.01 mg/kg to about 50 mg/kg of theactive compound of this invention when administered orally. Preferredoral doses will be about 0.01 to about 3.0 mg/kg, ideally about 0.01 toabout 0.1 mg/kg. When a present compound is given orally it may benecessary to administer the compound more than once each day, forexample about every eight hours. For IV administration by bolus, thedose will be from about 10 μg/kg to about 300 μg/kg, preferably about 20μg/kg to about 50 μg/kg.

The following experiments were conducted to demonstrate the ability ofthe compounds of Formula 1 to bind to 5-HT receptors. Such experimentsdemonstrate the utility of the compounds of Formula 1 in treatingdisease states (such as those noted above) which require alteration of5-HT receptor function.

The affinities of certain of the compounds of Formula 1 at the central5-HT_(1A) receptors were determined using a modification of the bindingassay described by Taylor et al., J. Pharmacol. Exp. Ther. 236, 118-125(1986). Membranes for the binding assay were prepared from maleSprague-Dawley rats (150-250 g). The animals were killed bydecapitation, and the brains were rapidly chilled and dissected toobtain the hippocampi. Membranes from the hippocampi were eitherprepared that day, or the hippocampi were stored frozen (-70° C.) untilthe day of preparation. The membranes were prepared by homogenizing thetissue in 40 volumes of ice-cold Tris-HCl buffer (50 mM, pH 7.4 at 22°C.) using a Techmar Tissumizer (setting 65 for 15 sec), and thehomogenate was centrifuged at 39800×g for 10 minutes. The resultingpellet was then resuspended in the same buffer, and the centrifugationand resuspension process was repeated three additional times to wash themembranes. Between the second and third washes the resuspended membraneswere incubated for 10 minutes at 37° C. to facilitate the removal ofendogenous ligands. The final pellet was resuspended in 67 mM Tris-HCl,pH 7.4, to a concentration of 2 mg of tissue original wet weight/200 μl.This homogenate was stored frozen (-70° C.) until the day of the bindingassay. Each tube for the binding assay had a final volume of 800 μl andcontained the following: Tris-HCl (50 mM), pargyline, (10 μM), CaCl₂ (3mM), [³ H]8-OH-DPAT (1.0 nM), appropriate dilutions of the drugs ofinterest, and membrane resuspension equivalent to 2 mg of originaltissue wet weight, for a final pH of 7.4. The assay tubes were incubatedfor 10 minutes at 37° C. and the contents were then rapidly filteredthrough GF/B filters (pretreated with 0.5% polyethylenimine), followedby four 1 ml washes with ice-cold buffer. The radioactivity trapped bythe filters was quantitated by liquid scintillation spectrometry, andspecific [³ H]8-OH-DPAT binding to the 5-HT_(1A) sites was defined asthe difference between [³ H]8-OH-DPAT bound in the presence and absenceof 10 μM 5-HT.

The results of the evaluation of various compounds of Formula 1 in thetest system described above are set forth in Table 1, below. In Table 1,the first column provides the Example Number of the compound evaluatedwhile the second column provides the amount of test compound (expressedin nanomolar concentration) required to inhibit the binding of [³H]8-OH-DPAT by 50% (indicated as IC50).

                  TABLE 1                                                         ______________________________________                                        IN VITRO BINDING ACTIVITY AT THE 5-HT1A RECEPTOR                                           5-HT1A                                                           Example      in vitro binding                                                 No.          (IC.sub.50, nM)                                                  ______________________________________                                        6            6.37                                                             7            1.95                                                             8            0.91                                                             10           0.73                                                             11           2.08                                                             12           105.00                                                           13           21.09                                                            14           5.30                                                             15           2.74                                                             17           17.34                                                            18           1.92                                                             ______________________________________                                    

The affinities of certain of the compounds of Formula 1 at the central5-HT_(1D) binding sites were determined using a modification of thebinding assay described by Heuring and Peroutka, J. Neurosci., 7, 894(1987). Bovine brains were obtained and the caudate nuclei weredissected out and frozen at -70° C. until the time that the membraneswere prepared for the binding assays. At that time the tissues werehomogenized in 40 volumes of ice-cold Tris-HCl buffer (50mM, pH 7.4 at22° C.) with a Techmar Tissumizer (setting 65 for 15 sec), and thehomogenate was centrifuged at 39,800×g for 10 minutes. The resultingpellet was then resuspended in the same buffer, and the centrifugationand resuspension process was repeated three additional times to wash themembranes. Between the second and third washes the resuspended membraneswere incubated for 10 minutes at 37° C. to facilitate the removal ofendogenous 5-HT. The final pellet was resuspended in the buffer to aconcentration of 25 mg of original tissue wet weight/ml for use in thebinding assay. Each tube for the binding assay had a final volume of 800μl and contained the following: Tris-HCl (50 mM), pargyline (10 μM),ascorbate (5.7 mM), CaCl₂ (3 mM), 8-OH-DPAT (100 nM to mask 5-HT_(1A)receptors), mesulergine (100 nM to mask 5-HT_(1C) receptors), [³ H]5-HT(1.7-1.9 nM), appropriate dilutions of the drugs of interest, andmembrane resuspension equivalent to 5 mg of original tissue wet weight,for a final pH of 7.4. The assay tubes were incubated for 10 minutes at37° C. and the contents were then rapidly filtered through GF/B filters(pretreated with 0.5% polyethylenimine), followed by four 1 ml washeswith ice-cold buffer. The radioactivity trapped by the filters wasquantitated by liquid scintillation spectrometry, and specific [³ H]5-HTbinding to the 5-HT_(1D) sites was defined as the difference between [³H]5-HT bound in the presence and absence of 10 μM 5-HT.

The results of the evaluation of various compounds of Formula 1 in thetest system described above are set forth in Table 2, below. In Table 2,the first column provides the Example Number of the compound evaluatedwhile the second column provides the amount of test compound (expressedin nanomolar concentration) required to inhibit the binding of [³ H]5-HTby 50% (indicated as IC₅₀).

                  TABLE 2                                                         ______________________________________                                        IN VITRO BINDING ACTIVITY AT THE 5-HT1D RECEPTOR                                           5-HT1D                                                           Example      in vitro binding                                                 No.          (IC.sub.50, nM)                                                  ______________________________________                                        6            30.00                                                            7            23.58                                                            8            9.12                                                             10           11.24                                                            11           1375.00                                                          13           1887.62                                                          14           43.14                                                            15           19.40                                                            17           163.02                                                           18           40.29                                                            ______________________________________                                    

The compounds of the present invention are preferably formulated priorto administration. Therefore, yet another embodiment of the presentinvention is a pharmaceutical formulation comprising a compound of theinvention and a pharmaceutically acceptable excipient therefor. Thepresent pharmaceutical formulations are prepared by known proceduresusing well known and readily available ingredients. In making thecompositions of the present invention, the active ingredient willusually be mixed with an excipient, diluted by an excipient or enclosedwithin an excipient serving as a carrier which can be in the form of acapsule, sachet, paper or other container. When the excipient serves asa diluent, it can be a solid, semi-solid or liquid material which actsas a vehicle, carrier or medium for the active ingredient. Thus, thecompositions can be in the form of tablets, pills, powders, lozenges,sachets, cachets, elixirs, suspensions, emulsions, solutions, syrups,aerosols (as a solid or in a liquid medium), ointments containing forexample up to 10% by weight of the active compound, soft and hardgelatin capsules, suppositories, sterile injectable solutions andsterile packaged powders.

Some examples of suitable excipients include lactose, dextrose, sucrose,sorbitol, mannitol, starches, gum acacia, calcium phosphate, alginates,tragacanth, gelatin, calcium silicate, microcrystalline cellulose,polyvinylpyrrolidone, cellulose, water, syrup, and methyl cellulose. Theformulations can additionally include lubricating agents such as talc,magnesium stearate and mineral oil, wetting agents, emulsifying andsuspending agents, preserving agents such as methyl andpropylhydroxybenzoates, sweetening agents or flavoring agents. Thecompositions of the invention may be formulated so as to provide quick,sustained or delayed release of the active ingredient afteradministration to the patient by employing procedures well known in theart.

The compositions are preferably formulated in a unit dosage form, eachdosage containing from about 0.5 to about 50 mg, more usually about 1 toabout 10 mg of the active ingredient. The term "unit dosage form" refersto physically discrete units suitable as unitary dosages for humansubjects and other meals, each unit containing a predetermined quantityof active material calculated to produce the desired therapeutic effect,in association with a suitable pharmaceutical excipient.

The following formulation examples are illustrative only and are notintended to limit the scope of the invention in any way.

Formulation 1

Hard gelatin capsules are prepared using the following ingredients:

    ______________________________________                                                           Quantity (mg/capsule)                                      ______________________________________                                        (+)-6-(3-isoxazolyl)-4-(di-n-                                                                      25                                                       propylamino)-1,2,2a,3,4,5-hexa-                                               hydrobenz[cd]indole                                                           Starch, dried        425                                                      Magnesium stearate   10                                                       Total                460       mg                                             ______________________________________                                    

The above ingredients are mixed and filled into hard gelatin capsules in460 mg quantities.

Formulation 2

A tablet formula is prepared using the ingredients below:

    ______________________________________                                                        Quantity (mg/tablet)                                          ______________________________________                                        (±)-6-[3-(5-aminothiazolyl)]-4-                                                              25                                                          (di-n-propylamino)-1,2,2a,3,4,5-                                              hexahydrobenz[cd]indole                                                       Cellulose, microcrystalline                                                                     625                                                         Colloidal silicon dioxide                                                                       10                                                          Stearic acid      5                                                           ______________________________________                                    

The components are blended and compressed to form tablets each weighing665 mg.

Formulation 3

A dry powder inhaler formulation is prepared containing the followingcomponents:

    ______________________________________                                                          Weight %                                                    ______________________________________                                        (±)-6-(5-isoxazolyl)-4-(di-n-                                                                  5                                                         propylamino)-1,2,2a,3,4,5-hexa-                                               hydrobenz[cd]indole                                                           Lactose             95                                                        ______________________________________                                    

The active compound is mixed with the lactose and the mixture added to adry powder inhaling applicance.

Formulation 4

Tablets each containing 60 mg of active ingredient are made up asfollows:

    ______________________________________                                        (+)-6-(2-pyrazolyl)-4-(di-n-                                                                          60     mg                                             propylamino)-1,2,2a,3,4,5-hexa-                                               hydrobenz[cd]indole                                                           Starch                  45     mg                                             Microcrystalline cellulose                                                                            35     mg                                             Polyvinylpyrrolidone (as 10%                                                                          4      mg                                             solution in water)                                                            Sodium carboxymethyl starch                                                                           4.5    mg                                             Magnesium stearate      0.5    mg                                             Talc                    1      mg                                             Total                   150    mg                                             ______________________________________                                    

The active ingredient, starch and cellulose are passed through a No. 20mesh U.S. sieve and mixed thoroughly. The solution ofpolyvinylpyrrolidone is mixed with the resultant powders which are thenpassed through a No. 4 mesh U.S. sieve. The granules so produced aredried at 50°-60° C. and passed through a No. 16 mesh U.S. sieve. Thesodium carboxymethyl starch, magnesium stearate and talc, previouslypassed through a No. 30 mesh U.S. sieve, are then added to the granuleswhich, after mixing, are compressed on a tablet machine to yield tabletseach weighing 150 mg.

Formulation 5

Capsules each containing 20 mg of medicament are made as follows:

    ______________________________________                                        (±)-6-(5-oxadiazolyl)-4-(di-                                                                       20     mg                                             methylamino)-1,2,2a,3,4,5-hexa-                                               hydrobenz[cd]indole                                                           Starch                  169    mg                                             Magnesium stearate      1      mg                                             Total                   190    mg                                             ______________________________________                                    

The active ingredient, cellulose, starch and magnesium stearate areblended, passed through a No. 20 mesh U.S. sieve, and filled into hardgelatin capsules in 190 mg quantities.

Formulation 6

Suppositories each containing 225 mg of active ingredient are made asfollows:

    ______________________________________                                        (+)-6-(4-pyridyl)-4-(di-n-propyl-                                                                      225    mg                                            amino)-1,2,2a,3,4,5-hexahydrobenz-                                            [cd]indole                                                                    Saturated fatty acid glycerides to                                                                     2,000  mg                                            ______________________________________                                    

The active ingredient is passed through a No. 60 mesh U.S. sieve andsuspended in the saturated fatty acid glycerides previously melted usingthe minimum heat necessary. The mixture is then poured into asuppository mold of nominal 2 g capacity and allowed to cool.

Formulation 7

Suspensions each containing 50 mg of medicament per 5 ml dose are madeas follows:

    ______________________________________                                        (±)-6-(2-thiazolyl)-4-(di-n-                                                                       50     mg                                             propylamino)-1,2,2a,3,4,5-hexa-                                               hydrobenz[cd]indole                                                           Xanthan gum             4      mg                                             Sodium carboxymethyl cellulose (11%)                                          Microcrystalline cellulose (89%)                                                                      50     mg                                             Sucrose                 1.75   g                                              Sodium benzoate         10     mg                                             Flavor                         q.v.                                           Color                          q.v.                                           Purified water to       5      ml                                             ______________________________________                                    

The medicament, sucrose and xanthan gum are blended, passed through aNo. 10 mesh U.S. sieve, and then mixed with a previously made solutionof the microcrystalline cellulose and sodium carboxymethylcellulose inwater. The sodium benzoate, flavor and color are diluted with some ofthe water and added with stirring. Sufficient water is then added toproduce the required volume.

Formulation 8

Capsules each containing 50 mg of medicament are made as follows:

    ______________________________________                                        (+)-6-(5-isoxazolyl)-4-(dimethyl-                                                                      50     mg                                            amino)-1,2,2a,3,4,5-hexahydrobenz-                                            [cd]indole                                                                    Starch                   507    mg                                            Magnesium stearate       3      mg                                            Total                    560    mg                                            ______________________________________                                    

The active ingredient, cellulose, starch and magnesium stearate areblended, passed through a No. 20 mesh U.S. sieve, and filled into hardgelatin capsules.

We claim:
 1. A compound of the formula ##STR15## wherein: R¹ ishydrogen, C₁ -C₄ alkyl, C₃ -C₄ alkenyl, cyclopropylmethyl, phenyl (C₁-C₄ alkyl), naphthyl (C₁ -C₄ alkyl), phenyl (C₁ -C₄ alkyl) substitutedwith one or two substituents selected from the group consisting of C₁-C₃ alkoxy, halo, hydroxy, C₁ -C₃ thioalkyl, nitro, C₁ -C₃ alkyl ortrifluoromethyl, naphthyl (C₁ -C₄ alkyl) substituted with one or twosubstituents selected from the group consisting of C₁ -C₃ alkoxy, halo,hydroxy, C₁ -C₃ thioalkyl, nitro, C₁ -C₃ alkyl or trifluoromethyl,--(CH₂)_(n) S(C₁ -C₄ alkyl), --C(O)R⁴, --(CH₂)_(n) C(O)NR⁵ R⁶ ;R² ishydrogen, C₁ -C₄ alkyl, cyclopropylmethyl or C₃ -C₄ alkenyl; R³ ishydrogen, C₁ -C₄ alkyl or an amino blocking group; n is 1-4; R⁴ ishydrogen, C₁ -C₄ alkyl, C₁ -C₄ haloalkyl, C₁ -C₄ alkoxy or phenyl; R⁵and R⁶ are independently hydrogen, C₁ -C₄ alkyl, or C₅ -C₈ cycloalkylwith the proviso that when one of R⁵ or R⁶ is a cycloalkyl the other ishydrogen; HET is a heterocyclic ring selected from the group consistingof ##STR16## where R is hydrogen, C₁ -C₃ alkyl, halogen, hydroxy, C₁ -C₃alkoxy, C₁ -C₃ thioalkyl, NH₂, CN or phenyl; or pharmaceuticallyacceptable salts thereof.
 2. The compounds of claim 1 wherein R¹ and R²are independently C₁ -C₃ alkyl or a pharmaceutically acceptable saltthereof.
 3. The compounds of claim 1 wherein R³ is hydrogen or apharmaceutically acceptable salt thereof.
 4. The compounds of claim 2wherein R³ is hydrogen or a pharmaceutically acceptable salt thereof. 5.The compounds of claim 1 wherein R¹ is --(CH₂)_(n) C(O)NR⁵ R⁶ wherein nis 2, R⁵ is hydrogen, R⁶ is cyclohexyl, R² is C₁ -C₃ alkyl, and R³ ishydrogen or C₁ -C₄ alkyl or a pharmaceutically acceptable salt thereof.6. The substantially pure stereoisomer of a compound of claim 1 or apharmaceutically acceptable salt thereof.
 7. The stereoisomer of claim 1wherein the configuration at position 2a is R and at position 4 is S ora pharmaceutically acceptable salt thereof.
 8. A pharmaceuticalformulation comprising a therapeutically effective amount of a compoundof claim 1 or a pharmaceutically acceptable salt thereof in combinationwith a pharmaceutically acceptable excipient therefor.
 9. A method fortreating a mammal with a serotonin-related disorder selected from thegroup consisting of anxiety, depression, excessive gastric acidsecretion, hypertension, nausea and vomiting, motion sickness, seniledementia, appetite disorders, alcoholism and smoking which comprisesadministering to said mammal an effective amount of a compound of claim1 or a pharmaceutically acceptable salt thereof.